1. Field of the Invention
This invention relates to a rack for a switchgear cabinet assembled from frame legs, which form a bottom frame in a bottom area of the switchgear cabinet, which encloses an opening that can be closed by bottom panels, and which can be or is connected with a base.
2. Description of Related Art
As a rule, the rack for a switchgear cabinet consists of twelve identical frame legs, as shown in German Patent Reference DE 33 44 598 C1. Here, increasing demands are made on the frame legs with respect to expanding options in the interior and the sealing of the wall elements and the cabinet door, which require an expensive rack. With these known racks the bottom frame is also constructed of four expensive frame legs, although as a rule it is only required in this area that bottom panels with cable connectors close the lower opening of the switchgear cabinet. In this case, often additional support profiles are connected with the bottom frame, on which the bottom panels rest and are fixed in place. This elaborate bottom frame requires a greater amount of space, which to a large extent is lost as installation space in the switchgear cabinet. Moreover, the known bottom frame with the support profiles makes the rack, and therefore the switchgear cabinet, more expensive.
It is one object of this invention to provide a rack of the type mentioned above but with a bottom frame that can be produced more cost-effectively, and which occupies less installation space in the switchgear cabinet and can be simply used for fastening the bottom panels.
In accordance with this invention this object is achieved with a bottom frame assembled from four cut to size U-profile sections and four square corner elements. The U-profile sections are open at the top, have an outer edge which is bent upward at right angles, and have an L-shaped inner edge oriented toward the outer edge. The corner elements cover the adjoining U-profile sections with fastening flanges and are connected with them, and the corner elements rest with an inside located angle bracket against the insides of the inner edges of the abutting U-profile sections and complete the outer edge of the bottom frame with an outside angle piece in the corner areas.
The U-profile sections are very simple and have only a low structural height. The corner elements are simple stamped and bent elements and complete the bottom frame by forming a closed unit. The L-shaped inner edge provides a simple support and fastening possibility for the bottom panels.
In accordance with one embodiment, the connection between the U-profile sections and the corner elements is provided so that the fastening flanges of the corner elements are offset in an upward direction and cover the abutting U-profile sections in the area of their base legs and are welded together with them.
In another embodiment, the corner elements are equipped with fastening receivers in their square base plates, and thus the bottom frame can be screwed together with the base of the switchgear cabinet, in a simple manner.
In accordance with one embodiment, there is a connection between the bottom frame and the vertical frame legs of the rack because the corner elements have upward oriented connecting flanges for attaching the vertical frame legs of the rack.
A simple fastening possibility for the bottom panels is created because the end sections of the L-shaped inner edges form support edges for support sections of bottom panels. The bottom panels are fixed in place on the L-shaped inner edges of the U-profile sections with U-shaped clamps having attachment screws.
The bottom opening of the rack can be divided because on facing sides the inner edge of the bottom frame has receivers oriented toward each other for a bisecting rail section, on which partial bottom panels are supported and fixed in place.